When a signal, even an ideal signal, is transmitted, the transmission channel and signal processing devices introduce signal distortions (multipath, noise, phase noise, etc.), which makes it more difficult to sort out the “true” transmitted signal at the receiving end. Distortions introduced by the transmission channel distortion(s) are time varying and are especially troublesome when dealing with certain classes of signals, such as ofdm signals. Some of the methods previously used to estimate the channel distortion require extensive use of supplementary signals, such as pilot signals, do not take account of variation of the distortion with time (frame-to-frame) or variation of the distortion with signal frequency.
What is needed is an approach that provides compensation for distortions of phase and other signal features in an in-phase/quadrature signal environment that is flexible, allows straight-through signal processing, has tolerable latency, accounts for frame-to-frame variation, and is relatively simple.